After succumbing to a fatal heart attack, Raizou Takakura finds himself reborn in a different realm as the impoverished farmer's third son, now known as Walm. Embracing life as a soldier in the war-torn Highserk Empire under siege by larger nations, Walm is thrust into a brutal existence of constant bloodshed. As the empire gears up for a monumental invasion against Myard and Ferrius, Walm grapples with the grim realities of war, witnessing the harrowing moments of both allies and foes meeting their ends and coming to understand the delicate balance between survival and mortality.